Keyless Chuck 

The CM/330/C, RD130C and RD140 can be adapted to
accept a 1/2" 3 jaw drill chuck. This chuck can be fitted
to all drill units having a 5/8" - 16 UNS output spindle nose.

Simply remove the bearing bracket, sleeve and arbor
or any other fittings. Place the chuck spacer onto the
spindle, screw the chuck tightly against the spacer
and lock in position.